DB<1> print $results
HASH(0x8421888)
# So $results stores a reference to a hash
DB<2> print join ', ', keys %$results
string
# So the hash has a single key, 'string'
DB<3> print $results->{string}
ARRAY(0x8421438)
# So the hash stores a reference to an array as the value for its only key
DB<4>print $results->{string}[0]
# This part left as an exercise for the reader.